Evolutionary relationship between yeast telomeric protein Cdc13 and Pot1

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Genetics

Background:

• The CST complex (CTC1, STN1, TEN1) protects telomere ss-overhangs.
• CTC1 is absent in some fungi, with Cdc13 substituting its function in Saccharomyces cerevisiae.
• Pot1 is the only Shelterin protein that binds ssDNA and is absent in Saccharomyces cerevisiae.

Purpose of the Study:

• To investigate the evolutionary history of CTC1, Cdc13, and Pot1 homologues in Fungi.
• To understand the functional substitution and evolution of telomere protection proteins in different fungal lineages.

Main Methods:

• Comparative genomics analysis of CTC1, Cdc13, and Pot1 homologues across Fungi.
• Phylogenetic analysis to infer evolutionary relationships and gene duplication events.

Main Results:

• CTC1 has been lost in Dikarya; its function is likely assumed by Pot1.
• Cdc13 likely evolved from Pot1 through domain loss, with Est3 becoming part of the telomerase complex.
• Gene duplication and fusion events in Cdc13 occurred in specific budding yeast orders.

Conclusions:

• The evolution of telomere protection proteins in Fungi involves gene loss, functional substitution, and domain evolution.
• Understanding these evolutionary pathways provides insights into the adaptability of telomere maintenance mechanisms.
• Findings can aid researchers in selecting novel yeast model organisms for telomere studies.